1. Field of the Invention
The present invention relates to a temperature sensor for detecting temperature. More particularly, the present invention relates to a temperature sensor device for detecting the temperature in a clean room.
2. Description of the Related Art
In manufacturing semiconductor devices, photolithography is used to form a fine pattern on a wafer. If dust or particles are attached to the wafer during the semiconductor manufacturing process, a failure may occur in the semiconductor device. Thus, dust and particles lower the yield of the manufacturing process and hence, add to the manufacturing cost of the semiconductor devices.
Therefore, a highly clean atmosphere has to be maintained for manufacturing semiconductor devices. Accordingly, semiconductor manufacturing lines are installed in a clean room.
In addition, because the semiconductor manufacturing process includes various manufacturing techniques that produce chemical reactions on a surface of the wafer, a change in temperature of the wafer affects the manufacturing process. For this reason, the temperature of the clean room is controlled such that the clean room always maintains a constant proper temperature.
Accordingly, a clean room temperature control device is provided to maintain the clean room at the proper temperature. The clean room temperature control device includes a temperature sensor device for detecting the temperature of the clean room.
Known temperature sensor devices include model TY7700B21 F manufactured by the YAMATAKE company of Japan, model SS-5030 manufactured by the KONICS company of Japan, and model Pt-100 manufactured by the MYUNGSUNG company of the Republic of Korea. However, these conventional temperature sensor devices are designed to detect the temperature in a specific liquid or poor environment and so, they are not suitable for precisely detecting the temperature of a clean room.
FIG. 1 shows a temperature sensor of a conventional temperature sensor device. As shown in FIG. 1, a temperature sensor element 10 is accommodated in a dual protecting tube that includes inner and outer protecting tubes 12 and 14. The dual protecting tube is designed to protect the temperature sensor element 10 from the external environment. The inner protecting tube 12 is filled with silicon sealant 16.
With this type of temperature sensor device, the temperature of the clean room can be detected only after a certain delay due to the provision of the dual protecting tube. That is, the temperature response of a clean room temperature control device incorporating the temperature sensor having the dual protecting tube is rather slow.
An object of the present invention is to overcome the above-described limitation of the prior art.
Therefore, one object of the present invention to provide a temperature sensor device that has a fast temperature response so as to be particularly well-suited for use in a clean room.
Still another object of the present invention is to provide a temperature sensor device that is easy to maintain and repair.
To achieve these objects, the temperature sensor device of the present invention has a temperature sensor whose sensor element is exposed to the atmosphere so that it is highly sensitive to changes in temperature change in the atmosphere.
The temperature sensor device of the present invention also has a housing, a covering tube extending from the housing, and a lead wire protecting tube disposed within the covering tube and extending from the housing. The temperature sensor is also disposed within the covering tube. A fixing end of the temperature sensor is detachably coupled to a distal end of the lead wire protecting tube. A plurality of lead wires of the temperature sensor extend into the housing through the lead wire protecting tube. The temperature sensor element is formed at a free end of the temperature sensor so as to be exposed to an atmosphere via at least one opening, in the covering tube, e.g. an opening at the distal end of the covering tube.
Preferably, the covering tube also has a plurality of perforations, i.e., radial holes, that allow the outside air to easily flow onto the temperature sensor element.
In order to facilitate the maintenance and repair of the temperature sensor device, the housing has an opening at a first portion thereof which is substantially opposite to the location at which the lead wire protecting tube is connected to the housing, and a lid is detachably coupled to the housing over the opening. The temperature sensor is also preferably threaded to the distal end of the lead wire protecting tube.